What tattoos really do to our bodies' immune systems
2019-10-10 22:10

(CNN)I lay on the mat of the open-air bungalow in Apia, Samoa, looking up at a gecko. As its tail quivered, I felt a sympathetic twitch in my leg. Su'a Sulu'ape Paulo III, the sixth-generation Samoan hand-tap tattoo master leaning over me, paused to see if my movement was due to pain.


I'd been in Samoa for a month, studying Samoan tattooing culture and the impact of the big traditional pieces called pe'a and malu -- tatau in general -- on the immune system. Now I was getting my own hand-tapped leg tattoo, albeit considerably smaller.


But one small study in the United States wasn't proof of anything -- despite headlines blaring that tattoos could cure the common cold. Good science means finding the same results multiple times and then interpreting them to understand something about the world.


That's why I traveled in 2018 with fellow anthropologist Michaela Howells to the Samoan Islands. Samoans have a long, continuous history of extensive tattooing. Working with contemporary machine and hand-tap tattooists in American Samoa, we wanted to see if we'd find the same link to enhanced immune response.


Immune defenders rush to tattoo's tiny wounds


More than 30% of Americans are tattooed today. Yet, few studies have focused on the biological impact beyond risks of cancer or infection.


Tattooing creates a permanent image by inserting ink into tiny punctures under the topmost layer of skin. Your body interprets a new tattoo as a wound and responds accordingly, in two general ways.


Innate immune responses involve general reactions to foreign material. So getting a new tattoo triggers your immune system to send white blood cells called macrophages to eat invaders and sacrifice themselves to protect against infection.


Your body also launches what immunologists call adaptive responses. Proteins in the blood will try to fight and disable specific invaders that they recognize as problems. There are several classes of these proteins -- called antibodies or immunoglobulins -- and they continue to circulate in the bloodstream, on the lookout lest that same invader is encountered again. They're at the ready to quickly launch an immune response the next time around.


This adaptive capacity of the immune system means that we could measure immunoglobulins in saliva as approximations of previous stress caused by tattooing.


In American Samoa, Howells and I worked at the Historic Preservation Office to recruit study participants with help from tattoo artists Joe Ioane of Off Da Rock Tattoos, Duffy Hudson of Tatau Manaia and traditional hand-tap tattooist Su'a Tupuola Uilisone Fitiao. Our sample of 25 tattoo recipients included both Samoans and tourists to the island.

在美萨摩亚,豪厄尔斯和我在历史保护办公室工作,在Off Da Rock的纹身艺术家乔·伊奥恩、塔图马纳亚的达菲·哈德森和传统的手工纹身师苏阿·图普奥拉·乌伊莱松·菲迪奥的帮助下招募研究参与者。25名纹身接受者样本包括萨摩亚人和岛上的游客。

We collected saliva at the start and end of each tattoo session, controlling for the tattoo duration. We also measured recipients' weight, height and fat density to account for health. From the saliva samples, we extracted the antibody immunoglobulin A, as well as the stress hormone cortisol and inflammatory marker C-reactive protein. Immunoglobulin A is considered a frontline immune defense and provides important protections against frequent pathogens like those of the common cold.


By comparing the levels of these biological markers, we determined that immunoglobulin A remains higher in the bloodstream even after tattoos heal. Furthermore, people with more time under the tattoo needle produced more salivary immunoglobulin A, suggesting an enhanced immune response to receiving a new tattoo compared to those with less or no tattoo experience. This effect appears to be dependent on receiving multiple tattoos, not just time passed since receiving one. This immune boost may be beneficial in the case of other skin injuries and for health in general.


Tattooing seems to exert a priming effect: That's what biologists call it when naive immune cells are exposed to their specific antigen and differentiate into antibodies that remain in the bloodstream for many years. Each tattoo prepares the body to respond to the next.


Other studies find that short-term stress benefits the immune system. Stress's bad rap comes from chronic forms that really do undermine immune response and health. But a little bit is actually good for you and prepares your body to fight off germs. Regular exercise provides immune function benefits through repetition, not necessarily single visits to the gym. We think this is similar to how each tattoo seems to prepare the body for vigilance.


Our Samoan findings supported the results of my first study in Alabama. But of course correlation does not imply causation. Enhanced immune response is correlated with more tattoo experience, but maybe healthier people heal easily from tattooing and like to get them more. How could we find out if getting tattoos could actually make a person healthier?


'Tatau belongs to Samoa'


Samoans have the oldest continuous tattoo culture in the Pacific Islands. Though many Samoans complain that young people are getting tatau for fashion, most get them to honor their heritage, saying their tattoo belongs not to them but to Samoan culture.


Samoans usually obtain permission from family to receive pe'a and malu. Getting and wearing these tattoos involve many responsibilities and indicate willingness to serve one's community.


Several of the Samoans in our sample had little interest in getting other tattoos, and one even reported being afraid of needles. They get pe'a and malu for the importance of these tattoos to their cultural identity, not because they are fashionable ways to show off. The social expectations for Samoans mean that getting pe'a or malu is less about self-motivated fashion choices than getting a tattoo is in the U.S. This is why Samoa is a great place to investigate whether the immune bump we see after tattooing is due to healthier people going under the needle in the first place -- in Samoa people of all body types and walks of life get them, from priests to politicians.


In July 2019 I focused on collecting multiple biological samples from people getting intensive tattoos in Apia, where they are administered daily in the center of town. I collected around 50 saliva samples from a dozen participants that will be analyzed in the coming year by anthropological immunologist Michael Muehlenbein.

在2019年7月,我专注于从阿皮亚接受强烈纹身的人们那里收集多个生物样本,每天在镇中心对它们进行管理。 我从十几个参与者那里收集了大约50个唾液样本,这些样本将在明年被人类学免疫学家迈克尔·穆伦贝因分析。

An evolutionary take on tattoos


Tattoos may provide visual evidence that others home in on to identify healthy mates or hardy friends. Such signals of fitness have been compared to peacock tail feathers, which would be too much of a burden if the peacock were not hale enough to escape predators.

纹身可能会提供视觉证据,表明他人在家中可以找到健康的伴侣或耐心的朋友。 此类健身信号像是孔雀尾羽毛一样,如果孔雀毛不够硬朗来逃避捕食者,那将是一个沉重的负担。

Even in the modern environment with improved health care, tattoos may "up the ante" by artificially injuring the body to demonstrate health. In a study I conducted among nearly 7,000 undergraduates, male intercollegiate athletes in general and football players in particular were more likely to be tattooed than nonathletes and less likely to suffer tattoo-related medical problems than those nonathletes who were tattooed.

即使在现代环境中,如果医疗保健得到改善,纹身可能会通过人为伤害身体以显示健康来“事前”。 在我对近7,000名大学生进行的一项研究中,男性普通大学生运动员,尤其是足球运动员比那些不运动的人更容易被纹身,与那些没有纹身的人相比,纹身相关的医疗问题更少。

The Conversation

It's not clear that the benefits tattooing provides are big enough to make a clinical difference on health, so don't expect a new tattoo to cancel out a diet of cheeseburgers and fries. But there is no doubt that tattooing is associated with toughness, and that we humans influence each other through impressions as much as reality.

目前尚不清楚纹身是否能带来足够的益处,从而在临床上改变健康状况,所以不要指望新的纹身能抵消起司汉堡和薯条的饮食。 但是毫无疑问,纹身与韧性有关,我们人类通过印象与现实相互影响。

0 条评论